COMPOSITION, DISTRIBUTION, AND EXCAVATION OF GYPSUM. 25 



The material occurs as rock gypsum, interbedded with shales and 

 shaly limestones of Carboniferous age. The beds of gypsum average 

 30 feet in thickness at the localities at which they are now worked. 

 The rocks of the district dip at a high angle, however, usually between 

 25 and 45, so that certain wells which have been drilled are in the 

 gypsum for long distances, and accordingly immense thicknesses of 

 gypsum have been erroneously reported, because the inclination of 

 the deposits was not taken into account. Near Saltville the dip of the 

 gypsum beds which are worked is toward the northwest; at the mines 

 farther up the valley the dip is to the southeast. 



The development of the gypsum industry in this area has been 

 governed almost entirely by the transportation facilities. The deposits 

 in the upper valley, though extensive and easily workable, have not 

 been largely exploited, owing to the long wagon-haul necessary. The 

 deposits at Saltville and Plasterco, which are on a branch of the Nor- 

 folk and Western Railroad, have furnished the principal output. 



Throughout the entire area the dip of the gypsum beds is so high 

 as to require mining, except at the commencement of the working. 



Wyoming. Though gypsum deposits occur at many localities in the 

 State, only two plaster-plants are at present in operation. These are 

 located at Laramie and Red Buttes respectively. A considerable exten- 

 sion of the Wyoming plaster industry may, however, be expected; for 

 the supplies of gypsum are large and accessible. 



Canada. Gypsum occurs in New Brunswick, associated with Lower 

 Carboniferious limestones, particularly large deposits being shown 

 near Hillsboro, Albert County. An analysis of a typical sample from 

 Hillsboro is given as no. 25, of Table 8, page 53. 



The gypsum deposits of Ontario occur in the form of beds, associated 

 with shales and limestones, in the Salina group. The principal exploited 

 deposits are located along the valley of Grand River, from Paris in 

 Brant County to near Cayuga in Haldimand County. 



Extensive gypsum beds also occur in Devonian limestones along the 

 Moose and French rivers, near James Bay: but these deposits are as 

 yet entirely undeveloped. 



In Nova Scotia thick beds of gypsum occur near St. John Harbor, 

 Port Bevis, and Baddeck Bay, associated with Carboniferous limestones. 

 An analysis of gypsum from near Baddeck Bay is given as no. 26 of 

 Table 8, page 53. 



Of the Canadian gypsum deposits, those of New Brunswick and 

 Nova Scotia are of interest to American producers, for they have sup- 

 plied large quantities of crude gypsum to plaster plants located in the 



